1. Field of the Invention
This invention relates generally to electroluminescent displays, and more particularly to a system and method for X-Y addressing of a panel having electroluminescent properties.
2. Description of the Prior Art
In 1937, G. Destriau in an article appearing in the Journal of Chemistry and Physics, Volume 34, Pages 117-124, described the production of luminescence by application of an electric field to phosphor powders. Since that time, many individuals have continued work in this area with flat-panel television display as their ultimate goal. Much of this work is summarized in an article by B. Kazan entitled "Electroluminescent Displays" appearing in IEEE Transactions on Consumer Electronics, Volume CE-21, No. 3, August 1975, pages 237-246. A further description of work done by others in this field appears in JANAIR Report No. 720903, AD-75 781, entitled "Electroluminescent Thin Film Research", dated July 15, 1972. An article by W. J. Harper entitled "Pulse Excitation of Electroluminescent Films" appeared in The Journal of Electrochemical Society for January 1963, pages 41-46.
As described in the aforementioned literature, in general electroluminescent panels have been addressed by a cross-grid, X-Y electrode structure on opposite sides of the panel. To excite a selected element defined by the cross-over or intersection point of an X electrode and a Y electrode, voltages are applied to the two electrodes of sufficient magnitude to excite the panel to luminescence at the cross-over point; however, one-half of the exciting voltage also appears across all of the remaining elements along the selected X and Y electrodes thus leading to a low contrast ratio. As further described in the above-mentioned literature, various methods have been tried for reducing the problem of cross-talk or excitation of unselected elements in order to increase resolution and contrast ratio .
U.S. Pat. No. 3,590,154, to Anthony C. Moricca discloses a flat panel display system employing a delay line with standing waves moved therealong in order to excite selected areas of the panel.